混凝土运输车中液压泵压力的影响外文文献翻译、中英文翻译

附录（英文文献和中文翻译）InvestigationonPressureImpactinConcretePumpingHydraulicSystemAbstract：Thepressureimpactinhydraulicsystemsofsuchconcretepumpingmachineryastrailerconcretepump，transportedconcretepump，andtruckmountedconcretepump，isakeyfactoraffectingtheirreliabilityandusagelife．Basedonthepressureformingprincipleoftheoilinahydrostaticclosedpressurechamber，themechanismofproducingpressureimpactisanalyzedsynthetically，andthetheorythatoilflowmatchesrequirement，andpumpdisplacementcontrolharmonizesvalveshiftingtimecontrol，tomitigatepressureimpact，isputforward．Thequantitativecontrollingparametersaboutshiftingtimeanddisplacementcontrolareintroducedtorealizeaccuratecontrol．Theexperimentinvestigationsofpressureimpactpropertyanditscontrolarecarriedthroughonanexperimentalsystemwhichisabletosimulateconcretepumpingcondition．Thebasiclawthatpressureimpactandcontrollingparametersvarywithworkingconditionrespectively．Thefeasibilityandvalidityofthetechnologyproposedinthispapertocontrolpressureimpactareconfirmed.Keywords:Pressureimpact；Hydraulicsystem；Concretepumpingmachinery．1IntroductionDuringworkingprocessofsuchconcretemachineryastrailerconcretepump，transportedconcretepump，andtruckmountedconcretepump，twooilcylindersdrivetwoconcretedeliverycylindersrespectively，andquicklyswitchdirectionwiththepossiblehighestfrequencyofmorethan30timesperminute，whichgeneratesserioushydraulicimpact．Itisanimportantfactorresultinginbadperformanceandlowusereliabilityofthemachine，andvibration，noiseandoverheatingetc．soit’sakeyofimprovingconcretepumpingmachinery’sreliabilitytogainamasteryofpressureimpactpropertyinconcretepumpinghydraulicsystemanditscontrollingtechnology．Suchtechnologicalmeasuresasfollowsweretakentoreducepressureimpact：(1)installationofahydraulicaccumulatororunloadingvalves，(2)changeofslidingspool’sstructure，(3)controloftheswitchingspeedofslidingspool，etc[1]．Thoughthesemeasuresplayanimportantroleinabsorptionofpressuresurges，thereareobviouslimitations，andtheyarepassivemeasures．Literature.2.investigatedtheswitchingprocessofconcretepumpinghydraulicsystem，andputforwardactivemeasureofregulatingoilpump’sdisplacementtoreducepressureimpact．Literature[3]studiedtheintrinsicrelationshipbetweenshiftingtimeandpressureimpact，andproposedanewconceptofoptimalshiftingtime．Therefore，inthispaper,experimentswereconductedtofindoutpressureimpactforminglaw，andbothoilpump’sdisplacementanddirectional—controlvalve’sshiftingtimewerecontrolledsimultaneouslytoseekoptimalcontrolschemeforeffectivereductionofpressureimpact．2ExperimentalprincipleThepressurevariationoftheoilinapressurechamberdependsuponthedifferencebetweenvolumesoftheoilflowinginandoutthechamber[2]．It’sobviousthateffectivereductionofthisdifferenceisofpositivesignificancefordepressingpressureimpact．Asfarasconcretepumpinghydraulicsystemisconcerned,thepressureimpactresultingfromthemainoilcylinders’stroketerminalliesuponthesuitabilityofshiftingtimetoagreatextent[3]．Soit’sfeasibleandeffectiveforabsorbingpressureimpacttoaccuratelycontroloilpump’sdisplacementaccordingtohydraulicsystem’srequirement，andcombineitwithshiftingtimecontroltechnique．WhatisshowninFig.1istheprincipledrawingoftheexperimentalsystemsuedtostudycharacteristicsofpressureimpactinconcretepumpinghydraulicsystemanditscontrollingtechniques．Themainoilpump(1)isaswash-platetypeaxialpistonpump，whichisprovidedwiththefunctionofconstanthorsepowercontrol。negativeflowcontr01．Thepressuredoilusedtocontr01oilpump’sdisplacementcomesfromtiltingsystem．Inthiscontrollingoilline，a3-way,2-positiondirectionalvalve(11)withonesolenoidandapressurereducingvalve(12)areinstalledinseries．Whenthesolenoidofvalve(11)isde-energized，thepressuredoilfromtiltingsystemisstopped，andthepressuredoilinthedisplacementcontroldeviceofoilpump(1)isintroducedintooilreservoirsimultaneouslybythevalve(11)．Here，theoilpressureinthedisplacementcontroldeviceiszeroorverylow，theoilpump’sdisplacementcancometomaximum．Ontheotherhand，whenthesolenoidofvalve(11)isenergized，thepressuredoilcomingfromtiltingsystemisintroducedbythevalve(11)，andisdecompressedbypressurereducingvalve(12)，andcomesintothedisplacementcontroldevice，so8stomakeoilpump’sdisplacementbereducedtominimumorzero.Twohydrauliccylinders(6.1,6.2)areconnectedinseries，andfourcheckvalvesandfourthrottlevalves，whichperformthefunctionsofsuctionandcushioning．areinstalledonthecylinders．Twonon-contactingsensors(9,10)areusedtoprovideshiftingsignals．FourpressuresensorsareinstalledatthetestingpointsM1，M2，M3andM4respectively．Thesignalsprovidedbythesesensorsarecollectedandanalyzedsynchronouslybyaspectruminstrumentandamicrocomputer．Thesamplingfrequencyis1kHz．Thesamplingtimeisoneminutesatatimesoastogainseveralpressuresignalsduringshiftingfromasampling．Duringtheexperimentalprocess，thepressuresignalsonlyduringsuchshiftingprocessasoilcylinders(6.1and6.2)extendsandretractstotheendrespectivelywereanalyzed．Whenthesensor(10)obtainsthesignalofcylinder(6.2)retractingstroketerminal，theelectricalsystemgivestheinstrumentforregulatingoilpump’sdisplacementtodecreaseitsswash-plate’sangle，andgivessignaltomakevalves(8，7)shiftafteracertaintime1ag．Duringsuchshiftingprocess，theshiftingtimeofvalve(1)dependsonfollowingtwofactors：oneisthesensor(10)’sinstallationpositionrelativetothecylinder(6.2)；theotheristheshiftingtimelag．i．e．thedifferencebetweenthetimeswhenmainoilpump(1)beginsregulatingdisplacementandwhenthehydro-piloteddirectionalcontr01valve(7)beginstoshift．Inordertosimplifytheexperiments，thesensor(10)’sinstallationpositionrelativetothecylinder(6.2)ischangeless，andtheoilpump’sdisplacementregulatingtimeisalsoinvariable．Thedifferencebetweenthetimeswhentheoilpump’sdisplacementbeginstoreduceandwhenbeginstoincreaseis0.2s．3ExperimentalresultsandanalysisFigure.2showsthecurvesofpressureversustime，whichweremeasuredatpointsM1andM2whentimelagAt.is0.12s．ItcanbeseenfromthecurvesshowninFig.2thatthepressureimpactextentinthechamberinwhichthetestingpointM1issituateddecreasesgraduallyalongwithanincreaseintheworkingpressure．Themainreasonisthatthepumpadoptsconstantpowercontrol，inresponsetotheriseoftheworkingpressure，theswash-plate’stiltingangleisdecreased，andpump’sdisplacementisreduced。themainoilcylinder’svelocitybecomessmaller．Sothepressureimpactdecreases．It’salsoseenfromFig.2thattherearetwopressurepeaksinthecurvesmeasuredattestingpointM1.Thetimeofproducingthosetwopressurepeakscorrespondswiththetwotransitionalpositionsofdirectionalcontrolvalve(7)duringitsspoolshifts．Figure．3showsthecurvesofpressureversustime，whichweremeasuredatpointsM1andM3whentimelagAt：is0.09s，andtheworkingpressureis10Mpa．ItcanbeseenfromFig．3thatthesecondpressurepeakinthecurvemeasuredatpointM1ismuchsmallerthanthefirstone．Themainreasonisasfollows：whentheslidingspoolofdirectionalcontrolvalve(7)movestothefirsttransitionalposition，it’simpossiblethatobviousvariationofswash—plate’stiltingangletakesplace，andtheoilflowisstillbig．Whentheslidingspoolofdirectionalcontrolvalve(7)movestothesecondtransitionalposition，swash-plate’stiltinganglehasbecomerelativelysmall，andtheoilflowisalsosmall．Therefore，thevolumedifferenceoftheoilbetweenflowinginandflowingoutthepressurechamberatthesecondtransitionalpositionismuchsmallerthanatthefirsttransitionalposition，whichresultsinthatthesecondpressurepeakismuchsmallerthanthefirstone．Itcanbeseen；byacomparisonbetweenFig．2(a)andFig．3，thatthetimelagAt：hasobviousinfluenceuponpressureimpactatthetestingpointM1．Tooshorttimelag.混凝土运输车中液压泵压力的影响摘要本文介绍了混凝土运输车中液压泵中的压力大小对整个液压系统的影响，液压泵的压力大小是影响整个工作系统的可靠性和使用寿命的关键因素，如何确定液压油在封闭液压缸中产生的压力的大小，要通过综合和理论上进行分析才能确定该工况下产生压力的影响，比如，油流量的要求，泵排量的控制，协调阀反应时间的控制，通过这些方面的控制，通过改变其中任何一个都可以减轻压力对整个系统的影响，只要通过定量控制这些参数的变化时间以及位移的控制就能做到，本文介绍了为实现准确控制，通过实验调查压力的影响以及控制其影响的实验系统，这个实验系统能够模拟混凝土泵在工作情况中的基本参数，这种压力的影响和控制参数的不同分别与工作条件的可行性和有效性的技术，本文提出了如何控制压力影响进行了验证。关键词压力的影响;液压系统;混凝土运输液压系统中的液压泵1简介在工作过程中，例如混凝土运输装置比如用卡车作为混凝土泵的运输装置，用来放置混凝土泵，混凝土运输车，两个汽油气缸来驱动两个具体交换气瓶分别和快速切换方向，频率最高能够超过30次每分钟，这会产生严重的液压冲击，这是一个重要因素对于增加系统的不良性能并且降低系统的可靠性，如何降低这种这种机器振动、噪声和系统温度过高的影响，关键的因素是增强混凝土机械泵的可靠性并且掌握压力的影响，完善混凝土运输系统中液压泵以及液压系统及其控制技术。采取如下几种措施可以减少压力对系统的影响；1安装液压储能器或卸载阀，2改变滑动阀芯的结构，3控制开关速度滑动阀芯等。虽然这些措施具有很重要的作用，可以吸收激增的压力，但还是有明显的局限性，他们是被动的措施，调查过程中对于具体的液压系统，提出了新的方法调节油泵流量，减少压力的影响，通过研究液压油流量时间和压力的内在影响，提出了新的方法来优化流量时间，因此，通过大量的实验在次基础下找出压力影响的规律，在油泵转速和方向阀的改变时间被控制的同时，寻求最佳控制计划，有效减少压力影响。2实验原理压力的变化取决于在压力室中液压油流入量与流出量之间的差异，很明显，有效的减少这种差别是具有重要意义的减少压力的影响。至于混凝土运送液压系统而言，压力造成的影响主要是液压油在液压缸终端的撞击的移动时间过快。所以根据液压系统的要求，可行和有效的吸收压力的影响，以及精确控制油泵流量和活塞运动时间的控制。如图1所示是研究压力影响的液压系统的原理图，混凝土运送系统的液压系统及其控制技术，主油泵1是一种柱塞泵，这是提供液压力的装置。出油控制对照来控制油泵系统，通过这个控制油路3个油路，2个换向阀11，同一个的电磁铁和降压阀12安装在一起。当电磁阀11断电时液压油换